Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit

Abstract

The process cartridge comprises a photosensitive drum having an axis L 1 and a coupling member having an axis L 2 . The coupling member includes (i) a first end portion connected to a drum flange, (ii) a second end portion, and (iii) a connecting portion connecting the first end portion and the second end portion. The coupling member is movable between (i) a first position in which a tip of the at least one projection is a first distance away from the photosensitive drum as measured in the direction of the axis L 1 and (ii) a second position in which the tip of the at least one projection is a second distance away from the photosensitive drum as measured in the direction of the axis L 1 , wherein the first distance is greater than the second distance.

What is claimed is: 
     
       1. A process cartridge comprising:
 a casing; 
 developer contained within the casing; 
 a photosensitive drum having an axis L 1 , the photosensitive drum being rotatably supported in the casing to permit rotation about the axis L 1 ; 
 a drum flange provided at an end of the photosensitive drum; and 
 a coupling member having an axis L 2  and including (i) a first end portion connected to the drum flange, (ii) a second end portion including at least one projection having a slanted surface with respect to a plane perpendicular to the axis L 2 , and (iii) a connecting portion connecting the first end portion and the second end portion, 
 wherein, as measured along a line perpendicular to the axis L 2 , a maximum distance from the axis L 2  to an outermost surface of the connecting portion is shorter than a distance between the axis L 2  and the at least one projection, and 
 wherein the coupling member is movable between (i) a first position in which a tip of the at least one projection is a first distance away from the photosensitive drum as measured in the direction of the axis L 1  and (ii) a second position in which the tip of the at least one projection is a second distance away from the photosensitive drum as measured in the direction of the axis L 1 , wherein the first distance is greater than the second distance. 
 
     
     
       2. A process cartridge according to  claim 1 , wherein at least a part of the first end portion is positioned within the drum flange. 
     
     
       3. A process cartridge according to  claim 2 , wherein the first end portion is restrained in the drum flange such that a relative movement between the photosensitive drum and the coupling member in a direction of the axis L 1  is limited. 
     
     
       4. A process cartridge according to  claim 1 , wherein, as measured along a line perpendicular to the axis L 2 , a maximum distance from the axis L 2  to the outermost surface of the connecting portion is shorter than a maximum distance from the axis L 2  to an outermost surface of the first end portion. 
     
     
       5. A process cartridge according to  claim 1 , wherein, for at least a part of the second end portion, a maximum distance from the axis L 2  to an outermost surface of the second end portion along a line perpendicular to the axis L 2  increases as the distance along the axis L 2  from the connecting portion increases. 
     
     
       6. A process cartridge according to  claim 1 , wherein the coupling member is movable between (i) a position in which the axis L 2  of the coupling member is coaxial with the axis L 1  of the photosensitive drum and (ii) an inclined position in which the axis L 2  of the coupling member is inclined with respect to the axis L 1  of the photosensitive drum, and
 wherein a maximum angle of inclination of the axis L 2  with respect to the axis L 1  is about 20 degrees to about 60 degrees. 
 
     
     
       7. A process cartridge comprising:
 a casing; 
 developer contained within the casing; 
 a photosensitive drum having an axis L 1 , the photosensitive drum being rotatably supported in the casing to permit rotation about the axis L 1 ; 
 a drum flange provided at an end of the photosensitive drum; and 
 a coupling member having an axis L 2  and including (i) a first end portion connected to the drum flange, (ii) a second end portion including at least one projection, with the at least one projection including a surface that extends at an obtuse angle from an adjacent surface of the second end portion, and (iii) a connecting portion connecting the first end portion and the second end portion, 
 wherein, as measured along a line perpendicular to the axis L 2 , a maximum distance from the axis L 2  to an outermost surface of the connecting portion is shorter than a distance between the axis L 2  and the at least one projection, and 
 wherein the coupling member is movable between (i) a first position in which a tip of the at least one projection is a first distance away from the photosensitive drum as measured in the direction of the axis L 1  and (ii) a second position in which the tip of the at least one projection is a second distance away from the photosensitive drum as measured in the direction of the axis L 1 , wherein the first distance is greater than the second distance. 
 
     
     
       8. A process cartridge according to  claim 7 , wherein at least a part of the first end portion is positioned within the drum flange. 
     
     
       9. A process cartridge according to  claim 8 , wherein the first end portion is restrained in the drum flange such that a relative movement between the photosensitive drum and the coupling member in a direction of the axis L 1  is limited. 
     
     
       10. A process cartridge according to  claim 7 , wherein, as measured along a line perpendicular to the axis L 2 , a maximum distance from the axis L 2  to the outermost surface of the connecting portion is shorter than a maximum distance from the axis L 2  to an outermost surface of the first end portion. 
     
     
       11. A process cartridge according to  claim 7 , wherein, for at least a part of the second end portion, a maximum distance from the axis L 2  to an outermost surface along a line perpendicular to the axis L 2  increases as the distance along the axis L 2  from the connecting portion increases. 
     
     
       12. A process cartridge according to  claim 7 , wherein the coupling member is movable between (i) a position in which the axis L 2  of the coupling member is coaxial with the axis L 1  of the photosensitive drum and (ii) an inclined position in which the axis L 2  of the coupling member is inclined with respect to the axis L 1  of the photosensitive drum, and
 wherein a maximum angle of inclination of the axis L 2  with respect to the axis L 1  is about 20 degrees to about 60 degrees. 
 
     
     
       13. A process cartridge comprising:
 a casing; 
 developer contained within the casing; 
 a photosensitive drum having an axis L 1 , the photosensitive drum being rotatably supported in the casing to permit rotation about the axis L 1 ; 
 a drum flange provided at an end of the photosensitive drum, the drum flange being configured to rotate with the photosensitive drum; and 
 a coupling member having an axis L 2  and including (i) a first end portion connected to the drum flange, (ii) a second end portion including at least one projection, and (iii) a connecting portion connecting the first end portion and the second end portion; and 
 an urging member configured to move the coupling member with respect to the drum flange, 
 wherein, as measured along a line perpendicular to the axis L 2 , a maximum distance from the axis L 2  to an outermost surface of the connecting portion is shorter than a distance between the axis L 2  and the at least one projection, 
 wherein the coupling member is movable between (i) a first position in which a tip of the at least one projection is a first distance away from the photosensitive drum as measured in the direction of the axis L 1  and (ii) a second position in which the tip of the at least one projection is a second distance away from the photosensitive drum as measured in the direction of the axis L 1 , wherein the first distance is greater than the second distance, and 
 wherein, in the direction of the axis L 1 , an outer end of the drum flange is more remote from the photosensitive drum than an outer end of the urging member is from the photosensitive drum. 
 
     
     
       14. A process cartridge according to  claim 13 , wherein at least a part of the first end portion is positioned within the drum flange, and
 wherein the first end portion is restrained in the drum flange such that a relative movement between the photosensitive drum and the coupling member in a direction of the axis L 1  is limited. 
 
     
     
       15. A process cartridge according to  claim 13 , wherein, as measured along a line perpendicular to the axis L 2 , a maximum distance from the axis L 2  to the outermost surface of the connecting portion is shorter than a maximum distance from the axis L 2  to an outermost surface of the first end portion. 
     
     
       16. A process cartridge according to  claim 13 , wherein, for at least a part of the second end portion, a maximum distance from the axis L 2  to an outermost surface of the second end portion along a line perpendicular to the axis L 2  increases as the distance along the axis L 2  from the connecting portion increases. 
     
     
       17. A process cartridge according to  claim 13 , further comprising a developing roller having an axis L 1 ′, the developing roller being configured to develop a latent image formed on the photosensitive drum with the developer, and the developing roller being rotatably supported in the casing to permit rotation about the axis L 1 ′,
 wherein the coupling member is operatively connected to the developing roller. 
 
     
     
       18. A process cartridge according to  claim 17 , wherein the casing includes an opening and at least one protrusion on an external portion of the casing adjacent to the opening. 
     
     
       19. A process cartridge according to  claim 18 , wherein the protrusion is provided adjacent to the coupling member with at least part of the connecting portion of the coupling member being uncovered to outside of the casing in a direction perpendicular to the axis L 1  away from the developing roller when the coupling member takes the first position. 
     
     
       20. A process cartridge according to  claim 13 , wherein the coupling member is movable between (i) a position in which the axis L 2  of the coupling member is coaxial with the axis L 1  of the photosensitive drum and (ii) an inclined position in which the axis L 2  of the coupling member is inclined with respect to the axis L 1  of the photosensitive drum, and
 wherein a maximum angle of inclination of the axis L 2  with respect to the axis L 1  is about 20 degrees to about 60 degrees. 
 
     
     
       21. A process cartridge comprising:
 a casing; 
 developer contained within the casing; 
 a photosensitive drum having an axis LL the photosensitive drum being rotatably supported in the casing to permit rotation about the axis L 1 ; 
 a drum flange provided at an end of the photosensitive drum, the drum flange being configured to rotate with the photosensitive drum; and 
 a coupling member having an axis L 2  and including (i) a first end portion connected to the drum flange, (ii) a second end portion including at least one projection, and (iii) a connecting portion connecting the first end portion and the second end portion; and 
 an urging member configured to move the coupling member with respect to the drum flange, 
 wherein, as measured along a line perpendicular to the axis L 2 , a maximum distance from the axis L 2  to an outermost surface of the connecting portion is shorter than a distance between the axis L 2  and the at least one projection, 
 wherein the coupling member is movable between (i) a first position in which a tip of the at least one projection is a first distance away from the photosensitive drum as measured in the direction of the axis L 1  and (ii) a second position in which the tip of the at least one projection is a second distance away from the photosensitive drum as measured in the direction of the axis L 1 , wherein the first distance is greater than the second distance, and 
 wherein at least part of the urging member is surrounded by the drum flange. 
 
     
     
       22. A process cartridge according to  claim 21 , wherein at least a part of the first end portion is positioned within the drum flange, and
 wherein the first end portion is restrained in the drum flange such that a relative movement between the photosensitive drum and the coupling member in a direction of the axis L 1  is limited. 
 
     
     
       23. A process cartridge according to  claim 21 , wherein, as measured along a line perpendicular to the axis L 2 , a maximum distance from the axis L 2  to the outermost surface of the connecting portion is shorter than a maximum distance from the axis L 2  to an outermost surface of the first end portion. 
     
     
       24. A process cartridge according to  claim 21 , wherein, for at least a part of the second end portion, a maximum distance from the axis L 2  to an outermost surface of the second end portion along a line perpendicular to the axis L 2  increases as the distance along the axis L 2  from the connecting portion increases. 
     
     
       25. A process cartridge according to  claim 21 , further comprising a developing roller having an axis L 1 ′, the developing roller being configured to develop a latent image formed on the photosensitive drum with the developer, and the developing roller being rotatably supported in the casing to permit rotation about the axis L 1 ′,
 wherein the coupling member is operatively connected to the developing roller. 
 
     
     
       26. A process cartridge according to  claim 25 , wherein the casing includes an opening and at least one protrusion on an external portion of the casing adjacent to the opening. 
     
     
       27. A process cartridge according to  claim 26 , wherein the protrusion is provided adjacent to the coupling member with at least part of the connecting portion of the coupling member being uncovered to outside of the casing in a direction perpendicular to the axis L 1  away from the developing roller when the coupling member takes the first position. 
     
     
       28. A process cartridge according to  claim 21 , wherein the coupling member is movable between (i) a position in which the axis L 2  of the coupling member is coaxial with the axis L 1  of the photosensitive drum and (ii) an inclined position in which the axis L 2  of the coupling member is inclined with respect to the axis L 1  of the photosensitive drum, and
 wherein a maximum angle of inclination of the axis L 2  with respect to the axis L 1  is about 20 degrees to about 60 degrees. 
 
     
     
       29. A process cartridge according to  claim 1 , further comprising a developing roller having an axis L 1 ′, the developing roller being configured to develop a latent image formed on the photosensitive drum with the developer, and the developing roller being rotatably supported in the casing to permit rotation about the axis L 1 ′,
 wherein the coupling member is operatively connected to the developing roller. 
 
     
     
       30. A process cartridge according to  claim 7 , further comprising a developing roller having an axis L 1 ′, the developing roller being configured to develop a latent image formed on the photosensitive drum with the developer, and the developing roller being rotatably supported in the casing to permit rotation about the axis L 1 ′,
 wherein the coupling member is operatively connected to the developing roller.